An 18-month-old Texas girl was allegedly punched in the face and stomped to death before being buried under a bridge in her diaper last Friday by her 17-year-old mother's boyfriend, who called her the "little demon."

In a shocking report by the Star-Telegram, little Tylea Moore's brutalized body was discovered buried under a bridge in Springtown, Texas, wrapped in a blanket. Her mother, Alexis Botello, had initially reported her missing before confessing to police that it was her boyfriend, Joshua Markus Beard, 20, who had killed her daughter, but noted that "he said he didn't mean to do it."

Beard, who was already in jail on an unrelated charge, was charged with capital murder on Monday. Botello, who helped her boyfriend dig her daughter's grave, has not been charged with a crime.

According to an affidavit reported by the Star-Telegram, the couple were in their Arlington, Texas, home when Beard began pushing and screaming at the toddler. Botello said she screamed back at Beard but he just kept on hitting the child over and over again leaving bruises, including bite marks.

Botello said Beard then threw her daughter on a bed and she bounced off and landed on the floor where he proceeded to stomp in her stomach. Little Tylea stopped breathing at some point during the abuse and the couple tried to revive her with CPR, but she died.

Beard reportedly placed Tylea's body in the trunk of her mother's car and drove to Parker County with her mother to bury her. They bought shovels and gloves at a Walmart along the way.

After the child was buried the couple rented a room at the Extended Stay hotel in Arlington, but investigators aren't sure why.

On Saturday, police arrested Beard on drug charges and traffic violations, and he was jailed. He then tried calling Botello repeatedly until he was forced to call his aunt, Trina McKenzie, who found Botello at the hotel.

McKenzie asked Botello where her daughter was and she was told that Tylea was with Botello's mother.

McKenzie, however, told investigators that she spoke with Tylea's grandmother who told her that she hadn't seen Tylea for more than a month.

On Sunday, Botello confessed that her daughter had been killed by Beard after police launched a search for Tylea at the hotel.

Tylea's father is reportedly a U.S. Marine slated to return to Arlington this week.